QR codes (Quick Response codes) were invented in 1994 by Denso Wave for tracking automotive parts. Twenty-five years later they're on restaurant menus, business cards, product packaging, event tickets, and city walls. Smartphone cameras scan them natively — no app required since iOS 11 and Android 8.
If you're generating QR codes for your business, project, or personal use, here's everything you need to know.
QR Code Content Types
QR codes encode text. But different formats of text unlock different behaviors when scanned:
URL
https://yoursite.com
The most common type. Opens the URL in the device's default browser. Best for marketing materials, business cards, and product packaging.
Plain Text
Any text you want to display when scanned. No special action is triggered — the text just appears on screen.
Email (mailto)
mailto:hello@yoursite.com?subject=Hello&body=I%20found%20your%20QR%20code
Opens a pre-addressed email compose window. Include subject and body to pre-fill the message — reduces friction for contact forms.
Phone (tel)
tel:+12125551234
Opens the phone dialer with the number pre-filled. Include the country code with + prefix for international compatibility.
Wi-Fi
WIFI:T:WPA;S:NetworkName;P:Password;;
Connects the device to a Wi-Fi network automatically (on supported platforms). Extremely useful for hotels, cafes, offices — eliminates the friction of typing passwords. iOS 11+ and Android 10+ support auto-connect.
SMS
sms:+12125551234?body=Hello%20there
Opens SMS app with number and optional pre-filled message. Good for two-factor authentication fallbacks and support workflows.
Size and Print Specifications
The minimum printable size for reliable scanning is 2.5cm × 2.5cm (1 inch) at a normal viewing distance. For outdoor signage or distance scanning, scale up proportionally.
| Use case | Minimum size | Recommended | |---|---|---| | Business card | 2.5cm × 2.5cm | 3cm × 3cm | | Flyer / poster | 3cm × 3cm | 5cm × 5cm | | Outdoor signage | 10cm × 10cm | 15cm × 15cm | | Billboards | Depends on viewing distance | 1m per 5m distance |
Always generate at high resolution. Use SVG for print (infinitely scalable) or PNG at 1200×1200px or higher. Never scale up a low-resolution raster QR code — the pixels become too large to scan reliably.
Color and Design
Standard QR codes are black on white. You can customize colors, but follow these rules:
Keep sufficient contrast. The scanner needs to distinguish dark modules (the squares) from the light background. Contrast ratio of at least 4:1. Don't use dark on dark or light on light.
Dark on light, always. Dark foreground on light background. Light on dark (inverted QR codes) is supported by most modern scanners but reduces compatibility with older devices.
Avoid adding too much to the center. Some QR tools let you embed a logo in the center. QR codes have error correction built in (up to 30% of modules can be damaged or obscured and it still scans). A small logo covering 20–25% of the center is generally safe.
Test before printing. Always scan your QR code with multiple devices (iPhone, Android, different apps) before committing to print.
Static vs Dynamic QR Codes
Static QR codes encode the destination directly. The URL is baked into the code — if you change your destination URL, you need a new QR code. Our generator creates static QR codes.
Dynamic QR codes encode a short redirect URL. The actual destination is stored server-side and can be changed without regenerating the code. They also enable analytics (scan count, location, device). Services like Bitly, QR Tiger, and Beaconstac offer dynamic codes.
Use static for permanent use cases (product packaging, books, permanent signage). Use dynamic when you might change the destination or need scan analytics.
Common Mistakes
Not testing on a real device before printing. Always scan with multiple phones before 1000 business cards go to print.
Using a web link without HTTPS. HTTP URLs get flagged as insecure by browsers. Always use HTTPS.
URL shorteners in QR codes are unnecessary. QR codes can encode long URLs without any performance penalty. The code gets slightly denser, but all modern scanners handle it. URL shorteners add a dependency on a third-party service.
Placing QR codes where phones can't focus. A QR code on a curved coffee cup, or under packaging tape, or in a window from outside — all create scanning problems. Place codes on flat, accessible surfaces.
Generate Yours Now
Our QR Code Generator supports URL, plain text, email, phone, Wi-Fi, and SMS content types. Customize foreground and background colors, adjust size, and download as PNG or SVG. Everything runs in your browser — no data is sent to any server.